XREF: a case study in Common Lisp portability

Abstract

Experience in building XREF, a Common Lisp cross reference utility, has revealed several issues relevant to writing portable program analysis utilities and supporting portable application programs across implementations. XREF is a program analyzer that parses Lisp code, analyzes calls to macros and functions and the use of variables, and then produces reports on inter-dependencies among functions, macros, variables, and files. It was designed to be a portable Common Lisp program that could analyze any any program written entirely in Common Lisp; the standard specified in [1] (hereafter CLtL) is both its implementation language and domain.